/*
 * Copyright (c) 2010 WiYun Inc.
 * Author: luma(stubma@gmail.com)
 *
 * For all entities this program is free software; you can redistribute
 * it and/or modify it under the terms of the 'WiEngine' license with
 * the additional provision that 'WiEngine' must be credited in a manner
 * that can be be observed by end users, for example, in the credits or during
 * start up. (please find WiEngine logo in sdk's logo folder)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package com.wiyun.engine.box2d.common;

import static java.lang.Math.*;

import com.wiyun.engine.types.WYPoint;

/**
 * Rotation
 */
public class Rotation {
	/// Sine
	public float s;
	
	/// cosine
	public float c;
	
	public static Rotation makeIdentity() {
		Rotation r = new Rotation();
		r.s = 0;
		r.c = 1;
		return r;
	}
	
	public static Rotation make(float angle) {
		Rotation r = new Rotation();
		r.s = (float)sin(angle);
		r.c = (float)cos(angle);
		return r;
	}
	
	protected Rotation() {
	}
	
	public void set(float angle) {
		s = (float)sin(angle);
		c = (float)cos(angle);
	}
	
	public void setIdentity() {
		s = 0;
		c = 1;
	}
	
	/**
	 * Get the angle in radians
	 */
	public float getAngle() {
		return (float)atan2(s, c);
	}

	/**
	 * Get the x-axis
	 */
	public WYPoint getXAxis() {
		return WYPoint.make(c, s);
	}

	/**
	 * Get the u-axis
	 */
	public WYPoint GetYAxis() {
		return WYPoint.make(-s, c);
	}
	
	public WYPoint mul(WYPoint v) {
		return WYPoint.make(c * v.x - s * v.y, s * v.x + c * v.y);
	}
}
